We love free stuff, especially free apps and services. But sometimes you need to pony up a little cash to get premium features—and sometimes those features are more than worth the money. We're curious: Which online services do you pay for?

Cloud storage services like Dropbox are one example of a kind of online service many people pay extra for (because they need more space to backup important files). Sometimes, also, you have to pay for the premium service option to get more functionality, like offline notebooks for mobile devices in Evernote. Other online services, like Amazon Prime shipping, are more conveniences than necessities, but still worth the cost for many people (though you can even get Prime for free if you have an EDU address or a child).